1. Field of the Invention
The present invention relates to a multi-connector used in a high-speed communication apparatus for signal connection of the high-speed communication apparatus, and a method for mounting the multi-connector into a printed board.
2. Description of the Related Art
As a multi-connector in a high-speed communication apparatus, there is used a multi-connector constituted by a pair of male and female connectors in each of which a large number of terminals are arranged in parallel at intervals of a predetermined pitch and fixed in a connector housing. FIGS. 5A and 5B are sectional views of male and female connectors in a multi-connector for use in a high-speed communication apparatus, for example, as disclosed in Japanese Patent Laid-Open No. Hei. 62736. In addition, FIG. 5C is a bottom view showing main part of the female connector depicted in FIG. 5B.
In FIG. 5A, each male terminal 1 has a signal terminal part 1c, and a ground terminal part 1b paired with the signal terminal part 1c. In FIG. 5B, each female terminal 2 has a signal terminal part 2c, and a ground terminal part 2b paired with the signal terminal part 2c. These male terminals are arranged at intervals of a predetermined pitch and fixed in a common connector housing 3. These female terminals are arranged at intervals of a predetermined pitch and fixed in a common connector housing 4. Thus, a multi-connector is constituted by the male and female connectors paired with each other. Each male terminal 1 (each female terminal 2) is divided into two terminal parts extending axially, that is, a signal terminal part 1c (2c) and a ground terminal part 1b (2b) so that impedance matching between the terminal parts is perfect. The signal terminal part 1c (2c) and the ground terminal part 1b (2b) are isolated from each other by an electrical insulator 1a (2a) having a predetermined dielectric constant and a predetermined thickness to form a predetermined value of impedance between the signal terminal part 1c (2c) and the ground signal part 1b (2b). For example, an electrical insulator 0.5 mm thick is used to form impedance of 50xcexa9 between the signal terminal part 1c (2c) and the ground signal part 1b (2b). Further, as shown in FIG. 5C which is a bottom view of main part of the female connector depicted in FIG. 5B, the electrical insulator 2a of the female terminal 2 has a width substantially equal to the distance between the signal terminal part 2c and the ground terminal part 2b. 
In a high-speed communication apparatus, a multi-connector constituted by a pair of male and female connectors is used for signal connection to a printed board. For example, as shown in FIG. 6A which is a sectional view showing connection between the connector and the printed board, and FIG. 6B which is a bottom view of FIG. 6A, the female terminal 2 of the multi-connector is connected into the printed board 6. In FIGS. 6A and 6B, the signal terminal part 2c and the ground terminal part 2b as electric pins are connected into through-holes 6a and 6b, respectively, in the printed board 6. A copper plating 7a (7b), for example, 1 xcexcm thick is applied to the inner circumference of each through-hole 6a (6b). A land portion 8a (8b) connected to the copper plating 7a (7b) is provided on the pattern wiring side of the printed board 6. That is, the copper plating 7a (7b) is connected to a copper pattern 9a (9b), for example, 12 xcexcm thick through the copper portion 8a (8b).
For the multi-connector used in the high-speed communication apparatus and the method of mounting the multi-connector into the printed board, it is necessary to widen the distance between the signal terminal part and the ground terminal part in accordance with the distance between two corresponding through-holes. For example, in the multi-connector for use in high-speed communication apparatus, the distance d1 between the signal terminal part 2c and the ground terminal part 2b is about 0.5 mm but the distance d2 between the through holes 6a and 6b is widened to about 2 mm because the land portions 8a and 8b are provided on the pattern wiring side of the printed board 6. For this reason, characteristic impedance between the signal terminal part and the ground apparatus has a problem in degradation of electrical characteristics.
The invention is developed for solving the problem. An object of the invention is to provide a multi-connector for use in a high-speed communication apparatus and a method for mounting the multi-connector into a printed board, in which the distance between each signal terminal part and a corresponding ground terminal part in the multi-connector for use in the high-speed communication apparatus need not be widened in the place for connection into the printed board when the signal terminal part and the ground terminal part in the multi-connector for use in the high-speed communication apparatus are attached into the printed board, so that characteristic impedance between the two terminal parts can be restrained from varying.
According to a first aspect of the invention, there is provided a multi-connector for use in a high-speed communication apparatus, the multi-connector including a male connector and a female connector. In the male connector, a plurality of terminals are arranged in parallel at intervals of a predetermined pitch and fixed in a first connector housing. In the female connector paired with the male connector, a plurality of terminals are arranged in parallel at intervals of a predetermined pitch and fixed in a second connector housing. Each of terminals is divided into two terminal parts extending axially. The two terminal parts are isolated from each other by an electrical insulator having a predetermined dielectric constant and a predetermined thickness. Knife edge-like end portions are formed on both sides of the electrical insulator in each of terminal parts of at least one of the male and female connectors. Accordingly, the distance between the two terminal parts need not be widened in the place for connection into the board to be connected. Hence, the multi-connector for use in the high-speed communication apparatus can be obtained so that characteristic impedance between the two terminal parts can be restrained from varying.
According to a second aspect of the invention, there is provided a method for mounting a multi-connector for use in a high-speed communication apparatus into a printed board. The multi-connector includes a male connector and a female connector. In the male connector, a plurality of terminals are arranged in parallel at intervals of a predetermined pitch and fixed in a first connector housing. In the female connector paired with the male connector, a plurality of terminals are arranged in parallel at intervals of a predetermined pitch and fixed in a connector housing. Each of terminals divided into two terminal parts extending axially and isolated from each other by an electrical insulator having a predetermined dielectric constant and a predetermined thickness. Knife edge-like end portions formed on both sides of the electrical insulator in each of the terminal parts of at least one of the male and female connectors. The printed board includes electrically conducting portions, pattern wiring portions, and land portions. The electrically conducting portions formed by applying an electrically high conductive plating to through-holes formed in the printed board to be connected to the multi-connector. The land portions are provided on a pattern wiring portion side and through which the electrically conducting portions are connected to the pattern wiring portions, respectively. The method includes the steps of inserting the connector having the knife edge-like end portions on the both sides of the electrical insulator into corresponding one of the through-holes of the printed board and three separating steps. In the first separating step, corresponding one of the electrically conducting portions is separated into a first electrically conducting part and a second electrically conducting part by the knife edge-like end portions. In the second separating step, corresponding one of the land portions is separated into a first land part and a second land part by the knife edge-like portions. In the third separating step, corresponding one of the pattern wiring portions is separated into a first pattern wiring part and a second pattern wiring part. Accordingly, the distance between the two terminal parts need not be widened in the place for connection to the printed board. Hence, a method for mounting a multi-connector for use in a high-speed communication apparatus into a printed board can be obtained so that characteristic impedance between the two terminal parts can be restrained from varying.
According to a third aspect of the invention, there is provided a method for mounting a multi-connector for use in a high-speed communication apparatus into a printed board. The multi-connector includes a male connector and a female connector. In the male connector, a plurality of terminals are arranged in parallel at intervals of a predetermined pitch and fixed in a connector housing. In the female connector paired with the male connector, a plurality of terminals are arranged in parallel at intervals of a predetermined pitch and fixed in a connector housing. Each of terminals divided into two terminal parts extending axially and isolated from each other by an electrical insulator having a predetermined dielectric constant and a predetermined thickness. The electrical insulator of each of terminals of at least one of the connectors having a linear portion sandwiched between the two terminal parts so as to extend linearly. Knife edge-shaped end portions being formed at both ends of the linear portion. The printed board includes electrically conducting portions, pattern wiring portions, and land portions. The electrically conducting portions are formed by applying an electrically high conductive plating to each of through-holes formed in the printed board to be connected to the multi-connector. The land portions are provided on a pattern wiring portion side and through which the electrically conducting portions are connected to the pattern wiring portions, respectively. The method includes the steps of inserting each terminal having the knife edge-like end portions at the both ends of the linear portion of the electrical insulator into corresponding one of the through-holes of the printed board and four separating steps. In the first separating step, corresponding one of the electrically conducting portions is separated into a first electrically conducting part and a second electrically conducting part by the linear portion. In the second separating step, corresponding one of the land portions is separated into a first land part and a second land part by the linear portion. In the third separating step, corresponding one of the pattern wiring portions is separated into a first pattern wiring part and a second pattern wiring part. Accordingly, the distance between the two terminal parts need not be widened in the place for connection to the printed board, and the connection portion of the board to be connected can be cut into two parts along the shape of the linear portion so that the two parts can be electrically connected to the terminal parts. Hence, variation in characteristic impedance between the two terminal parts can be set to be substantially equal to zero, or crosstalk can be reduced to zero in the place for connection.